The present disclosure relates to an audio signal processing apparatus and an audio signal processing method that perform correction processing on an audio signal in accordance with the arrangement of a multi-channel speaker.
In recent years, an audio system in which audio content is reproduced by multi-channels such as 5.1 channels has been prevailing. In such a system, it is assumed that speakers are arranged at predetermined positions with a listening position where a user listens to audio as a reference. For example, as the standard on the arrangement of speakers in a multi-channel audio system, “ITU-R BS775-1 (ITU: International Telecommunication Union)” or the like has been formulated. This standard provides that speakers should be arranged at an equal distance from a listening position and at a defined installation angle. Further, a content creator creates audio content on the assumption that speakers are arranged in conformity with the standard as described above. Accordingly, it is possible to produce original acoustic effects by properly arranging speakers.
However, in private households or the like, a user may have a difficulty in correctly arranging speakers at defined positions as provided in the standard described above due to restrictions such as the shape of a room and the arrangement of furniture or the like. Preparing for such a case, an audio system in which correction processing is performed on an audio signal in accordance with positions of arranged speakers has been realized. For example, Japanese Patent Application Laid-open No. 2006-101248 (paragraph [0020], FIG. 1; hereinafter, referred to as Patent Document 1) discloses “a sound field compensation device” that enables a user to input an actual position of a speaker with use of a GUI (Graphical User Interface). This device performs, when reproducing audio, delay processing, assignment of audio signals to adjacent speakers in accordance with the input position of the speaker, or the like and performs correction processing on the audio signals as if the speakers are arranged at proper positions.
In addition, Japanese Patent Application Laid-open No. 2006-319823 (paragraph [0111], FIG. 1; hereinafter, referred to as Patent Document 2) discloses “an acoustic device, a sound adjustment method and a sound adjustment program” that collect audio of a test signal with use of a microphone arranged at a listening position to calculate a distance and an installation angle of each speaker with respect to the microphone. This device performs, when reproducing audio, adjustment or the like of a gain or delay in accordance with the calculated distance and installation angle of each speaker with respect to the microphone and performs correction processing on audio signals as if the speakers are arranged at proper positions.